Nostalrius Begins - Quality wow vanilla realm (1.12)

I would like to report a problem with this skill. I'm not sure if it is working as intended but while waterwalking if I decide to go underwater I am not longer able to waterwalk again even though the buff is still active.

There's a lot more bugs to Water Walking than that one. But yes, that is a bug.
The other bugs of it are a lot more game breaking.